Search results for "Impulse response"

Splines Computation by Subdivision

2015

In this chapter, fast stable algorithms are presented, which compute splines’ values at dyadic and triadic rational points starting from their samples at integer grid points. The algorithms are implemented by the causal-anticausal recursive filtering of initial data samples, which is followed by iterated application of FIR filters. Extension of the algorithms to the multidimensional case is straightforward. A natural application of the presented subdivision algorithms is for upsampling of signals and images. A few upsampling examples are provided.

Non-periodic Discrete Splines

2015

Discrete Splines with different spans were introduced in Sect. 3.3.1. This chapter focuses on a special case of discrete splines whose spans are powers of 2. These splines are discussed in more detail. The Zak transform provides an integral representation of such splines. Discrete exponential splines are introduced. Generators of the discrete-spline spaces are described whose properties are similar to properties of polynomial-spline spaces generators. Interpolating discrete splines provide efficient tools for upsampling 1D and 2D signals. An algorithm for explicit computation of discrete splines is described.

Combination of finite impulse response neural network technique with FDTD method for simulation of electromagnetic problems

1996

The finite difference time domain (FDTD) method requires long computation times for simulating resonant or high-Q structures. The authors incorporate the finite impulse response neural network technique as a predictor in order to save time in FDTD simulations. The applicability of the technique is demonstrated by carrying out an analysis of a waveguide filter.

FDTD signal extrapolation using a finite impulse response neural network model

1999

An Impulse Response Model for the 60 Ghz Channel Based on Spectral Techniques of alpha-stable Processes

2007

International audience; In order to make realistic simulations of the radio propagation mechanism in ultra-wide band channels, an appropriate model is needed. In this paper we propose a new technique to model the impulse response of the 60 Ghz channel. This new approach is based on the spectral analysis of alpha-stable processes. Our new model presents many advantages: firstly, the channel is characterized only by a one deterministic function (spectral density) in the place of four parameters. Secondly, the estimations procedure deals directly with the measured transfer functions which avoids loosing information in data pretreatment. Finally, an estimation of the spectral measure permits to…

Binarization of a super-resolving graytone pupil filter by digital halftoning

1995

— Six digital-halftoning procedures, including one algorithm proposed by us, are compared to determine which one is best suited to binarization of a parabolic super-resolving pupil filter. The procedures we deal with include iterative, error-diffusion, error-convergence, and 1-pixel algorithms. We carry out a numerically simulated experiment in which an object that consists of either one point source or two coherent point sources is imaged in a 4f imaging system with either a continuous super-resolving parabolic filter or one of its six different binary versions. The performance of binary filters is examined in terms of two parameters: the resemblance of their amplitude impulse response (AI…

<title>Human cell texture analysis with quincunx spline wavelet transform</title>

1999

Wavelet transforms are efficient tools for texture analysis and classification. Separable techniques are classically used but present several drawbacks. First, diagonal coefficients contain poor information. Second, the other coefficients contain useful information only if the texture is oriented in the vertical and horizontal directions. So an approach of texture analysis by non-separable transform is proposed. An improved interscale resolution is allowed by the quincunx scheme and this analysis leads to only one detail image where no particular orientation is favored. New orthogonal isotropic filters for the decomposition are constructed by applying McClellan transform on one dimension B-…

ANALYZING THE EUROPEAN MARKET OF INTEREST RATE SWAP INDICES

2012

The interest rate risk is the most important risk that derives from the OTC transactions, taking into consideration both the notional amounts and the market value of the financial derivatives that relies on interest rate contracts. Open positions on interest rate derivatives represents more than 75% of the OTC market. In the European banking market interest rate swaps prices are strongly dependent on the interbank interest rates. In this paper we want to analyze the behavior of the Eoniaswap indices and their impact on the interest rate swaps between banks.

Random vibration mitigation of beams via tuned mass dampers with spring inertia effects

2019

The dynamics of beams equipped with tuned mass dampers is of considerable interest in engineering applications. Here, the purpose is to introduce a comprehensive framework to address the stochastic response of the system under stationary and non-stationary loads, considering inertia effects along the spring of every tuned mass damper applied to the beam. For this, the key step is to show that a tuned mass damper with spring inertia effects can be reverted to an equivalent external support, whose reaction force on the beam depends only on the deflection of the attachment point. On this basis, a generalized function approach provides closed analytical expressions for frequency and impulse res…

Application of Periodic Frames to Image Restoration

2014

In this chapter, we present examples of image restoration using periodic frames. Images to be restored were degraded by blurring, aggravated by random noise and random loss of significant number of pixels. The images are transformed by periodic frames designed in Sects. 17.2 and 17.4, which are extended to the 2D setting in a standard tensor product way. In the presented experiments, performances of different tight and semi-tight frames are compared between each other in identical conditions.